: I have an old garden tap at the end of a galvanised pipe. I want to remove the whole pipe, but cannot turn the supply off. I don't know where the pipe originates from because it disappears under the patio about 3 meters from the house. Operating the stopcock has no effect on the water flow. Is it possible to cut and cap such a pipe with the water still switched on?

There are several ways to stop the flow to cap the line at the threads or the garden cap, and a LICENSED plumber can freeze the line to do the job. Do you know where the water meter is that is used to calculate your water usage bill? you can turn off the water supply to the whole house there.